Metropolitan Transportation Authority police said two jewelry company employees were transporting the bag during rush hour at Grand Central on June 24.
The MTA said the employee with the bag put it down "momentarily" to throw away garbage.
That's when two suspects created a diversion by dropping a $10 bill on the ground, and telling the other jewelry employee that he had dropped the money.
A third suspect switched the bag for a nearly identical one that had been weighted down to appear as if it contained the jewelry.
